Path Of Steepest Ascent Research Articles

Optimization of submerged fermentation conditions for glucanase production by Burkholderia pyrrocinia B1213 using Jiuzao

This study optimized the fermentation conditions for producing glucanase from Burkholderia pyrrocinia B1213 using Jiuzao, a residue from Baijiu distillation, as the carbon source. The effects of Jiuzao particle size and concentration, type of nitrogen source, urea concentration, initial pH, inoculum size, loading volume, shaking speed, temperature, surfactant type and incubation time on glucanase production by B. pyrrocinia B1213 were investigated separately through single factor design. Then, five variables, Jiuzao concentration, inoculum size, initial pH, temperature and incubation time, were found to significantly affect glucanase production using the Plackett-Burman design. Following, the optimal conditions for glucanase production by B. pyrrocinia B1213 were found using the steepest ascent path and response surface methodology designs as: particle size, 40-60 mesh; Jiuzao concentration, 58.4 g/L; urea concentration, 8 g/L; initial pH, 6; loading volume, 15 mL/250 mL; inoculum size, 0.63% (v/v); temperature, 26 °C; shaking speed, 160 rpm; and incubation time, 120 h. Under these conditions, the glucanase activity of the B. pyrrcinia B1213 strain was 1336 U/mL, producing the biological enzymes needed in Baijiu making from a by-product. This study has provided experimental data and theoretical information for using B. pyrrcinia B1213 in Baijiu production. Keywords: Burkholderia pyrrocinia; Glucanase; Response surface methodology; Fermentation conditions; Jiuzao

Establishment and Calibration of Discrete Element Model for Buckwheat Seed Based on Static and Dynamic Verification Test

Aiming at the lack of accurate and reliable discrete element simulation parameters for the design of buckwheat metering devices and seeders based on the discrete element simulation method, an accurate buckwheat seed model was obtained by calibrating the discrete element simulation parameters. In this study, buckwheat seed particle models were established based on the manual and automatic filling methods. In order to improve the accuracy of the models, discrete element simulation parameters were calibrated, and the static cylinder-lifting test and dynamic seed-metering test were used to verify the simulation results. A 3D model of buckwheat seed was obtained using the CT scanning method, and a manual filling 7-sphere particle model and an automatic filling multi-sphere particle model were established. The physical parameters and contact parameters were measured using the uniaxial compression test, the drop test, and the friction coefficient measurement test. The Plackett–Burman test and steepest ascent path were used to obtain the optimal parameter combination based on the static cylinder-lifting test. We conducted dynamic seed-metering tests using the two particle models under the optimal parameter combination. The results show that, compared with the measured values of stacking angle, the relative errors of the simulation values of the manual filling 7-sphere and automatic filling 36-sphere particle models are 1.04% and 0.50%, respectively. When the rotation speed range of the seeding wheel is 20~60 r/min, the average relative errors between the simulated value and the measured value are 15.85% and 4.69%, respectively. When the effective working length range of the seeding wheel is 20~40 mm, the average relative errors between the simulated value and the measured value are 22.18% and 9.07%, respectively. Regardless of whether the manual filling 7-sphere or the automatic filling 36-sphere particle model of buckwheat seed was used for static motion parameter simulation or dynamic motion simulation, the automatic filling 36-sphere particle model has a higher accuracy. The buckwheat seed particle model established in this study will provide support for the design of buckwheat special seed-metering devices and improve the quality of buckwheat mechanized sowing operation.

Optimization of xylanase production from Aspergillus Spp. hau-f-6 using plackett burman screening design and path of steepest ascent in submerged fermentation

Optimization of xylanase production from Aspergillus Spp. hau-f-6 using plackett burman screening design and path of steepest ascent in submerged fermentation

Maximizing Adsorption Involving Three Solutes on Enhanced Adsorbents Using the Mixture-Process Variable Design.

Unmodified (UN), acid-treated (AT) and microwave-acid-treated (MAT) activated carbons were optimized for their solute removal efficacies by adjusting feed mixture compositions and process conditions. Acetaminophen, benzotriazole, and caffeine were used either individually or as binary/ternary mixtures in this study. The process conditions considered were the pH, adsorbent dosage, and type of adsorbent. Experimental responses such as total adsorbent loading (qtotal) and total percentage removal (PRtotal) were fitted with empirical models that had high adjusted R2 (>0.95), insignificant lack of fit (p-value > 0.22), and high model predictive R2 (>0.93). Mixture compositions of the feed were found to interact significantly not only among themselves but with process variables as well. Hence, adsorption optimization must simultaneously consider mixture as well as process variables. The conventional response surface methodology for mixtures, termed as ridge analysis, optimizes mixture compositions at specified values of process variables. An improved steepest ascent method which considers mixture and process variables simultaneously was developed in this work. This could track the path of steepest ascent toward globally optimal settings, from any arbitrary starting point within the design space. For the chosen adsorbent, optimal settings for feed mixture compositions and pH were found to change along this steepest ascent path. The feed compositions, pH, and adsorbent dosage identified for maximum adsorbent utilization were usually quite different from those identified for maximum total percentage removal. When both these objectives were optimized together, the most favorable compromise solutions for qtotal and PRtotal were, respectively, 264.1 mg/g and 43.4% for UN, 294.9 mg/g and 52.5% for AT, and 336.6 mg/g and 55.9% for MAT.

Response Surface Optimization of Dietary Iron, Calcium and Vitamin C in Soyamilk for Complementary Feeding

Response surface methodology (RSM) is a collection of tools developed in the 1950s for the purpose of determining optimum operating conditions. In this work, a three level three factor (33) factorial design that metamorphosed to the response surface design with two augmented central point was employed. In its applications a secondary data from the department of Food Science and Technology (FST), Michael Okpara University of Agriculture, Umudike (MOUAU), containing the mineral components of soymilk for complementary feeding of infants was used. The analysis for the First Order (FO), Two Way Interaction (TWI) and the Polynomial (PQ) model was carried out and the augmented response surface analysis was performed. Following the path of steepest ascent, an optimality condition from the surface and contour lines shows that dietary iron is significant for varying the colour content, while calcium was significant for varying the ash and moisture content. It was then recommended that for optimal colour content in the soymilk, 3.07mg/100ml of Dietary Iron, 154.1mg/100ml of Calcium and 24.23mg/100ml of Vitamin C should be used, for optimal ash content in the soymilk, 2.22mg/100ml of Dietary Iron, 152.03mg/100ml of Calcium and 13.53mg/100ml of Vitamin C should be used while for optimal moisture content in the soymilk, 2.9858mg/100ml of dietary Iron, 335.71mg/100ml of Calcium and 25.48mg/100ml of Vitamin C should be used.

Optimization of fermentation conditions for production of ethyl caproate in Baijiu using a selected isolate of Saccharomyces cerevisiae

Saccharomyces cerevisiae is indispensable in the production of Baijiu. This yeast not only produces ethanol, but also produces many flavorsubstances that impart unique quality characteristics to Baijiu. Ethyl caproate (EC) is the main flavor substance of strong-flavor Baijiu(SFB). S. cerevisiae that can produce a high yield of EC is critical for SFB production. In the present study, S. cerevisiae isolate YF1914produced an EC content of 1.27 mg/L, which was greater than that produced by other test isolates obtained from several Baijiu brewingenvironments. Through single factor experiments, the influence of various factors on EC production by YF1914 was measured. Eightvariables were tested using a Plackett-Burman design, and ethanol content, induction time, caproic acid content, initial pH, and temperaturesignificantly affected EC production. Further studies were done using the steepest ascent path and response surface methodology (RSM)designs to identify optimized fermentation conditions for EC production. The optimum conditions were found to be: sorghum hydrolysatemedium (SHM) with a sugar content of 12 Brix and an initial pH of 5.0, inoculum size 5% (v/v), incubation at 28 °C with shaking at180 rpm for 32 h, addition of 10% (v/v) ethanol and 0.046% (v/v) caproic acid at 32 h, then static culture at 24 °C for 32 h. Theoptimized conditions produced an EC content of 21.98 mg/L or 17.3 times greater than the content obtained using initial conditions. Thus,a selected S. cerevisiae isolate with high EC yield was obtained, which can potentially improve SFB quality by increasing EC content.Keywords: ethyl caproate; optimization; Saccharomyces cerevisiae; strong-flavor Baijiu

Bioprocess Optimization of Nutritional Parameters for Enhanced Anti-leukemic L-Asparaginase Production by Aspergillus candidus UCCM 00117: A Sequential Statistical Approach.

Sequential optimization of bioprocess nutritional conditions for production of glutaminase-near-free L-asparaginase by Aspergillus candidus UCCM 00117 was conducted under shake flask laboratory conditions. Catalytic and anti-cancer activities of the poly-peptide were evaluated using standard in vitro biochemical methods. Medium nutrients were selected by one-factor-at-a-time (OFAT) approach while Plackett–Burman design (PBD) screened potential factors for optimization. Path of steepest ascent (PSA) and response surface methodology (RSM) of a Min-Run-Res V fractional factorial of a central composite rotatable design (CCRD) were employed to optimize factor levels towards improved enzyme activity. A multi-objective approach using desirability function generated through predictor importance and weighted coefficient methodology was adopted for optimization. The approach set optimum bioprocess conditions as 49.55 g/L molasses, 64.98% corn steep liquor, 44.23 g/L asparagine, 1.73 g/L potassium, 0.055 g/L manganese and 0.043 g/L chromium (III) ions, at a composite desirability of 0.943 and an L-asparaginase activity of 5216.95U. The Sephadex-200 partially-purified polypeptide had a specific activity of 476.84 U/mg; 0.087U glutaminase activity, 36.46% yield and 20-fold protein purification. Anti-cancer activity potentials of the catalytic poly-peptide were dose-dependent with IC50 (µg/mL): 4.063 (HL-60), 13.75 (HCT-116), 15.83 (HeLa), 11.68 (MCF-7), 7.61 (HepG-2). The therapeutic enzyme exhibited 15-fold more cytotoxicity to myeloid leukemia cell line than to normal (HEK 238 T) cell. Optimum temperature and pH for activity were within physiological range. However, significant interactions between exposure time and levels of each of temperature and pH made interpretations of residual enzyme activities difficult. The manganese-dependent L-asparaginase from Aspergillu s candidus UCCM 00117 is recommended for further anticancer drug investigations.

Bacillus cereus liquid fertilizer was produced from Agaricus bisporus industrial wastewater

During the Agaricus bisporus canning processes, a large number of water-soluble elements were dissolved into the processing hot water. This study was conducted to use the industrial wastewater of A. bisporus to prepare agricultural microbial fertilizer. In the work, the influence of 6 different liquid fermentation factors on the total biomass of living Bacillus cereus was evaluated with the one-factor-at-a-time method and the Plackett–Burman design. The total biomass of living B. cereus was most influenced by fermentation temperature, shaking speed, and inoculation volume, which were identified as the most critical independent variables for the B. cereus biomass. The approximate ranges of optimal fermentation conditions for the three key factors were identified by the path of steepest ascent. The center point of these factors were 24 ℃ of temperature, 250 rpm of shaking speed and 12 % inoculum amount, respectively. The Box-Behnken design was applied to derive a statistical model for optimizing the three fermentation factors for B. cereus biomass. After further optimizations based on statistical predictions, the optimum fermentation parameters for B. cereus cultured in the A. bisporus industrial wastewater were fermentation temperature of 24.8 °C, shaking speed of 234 rpm, inoculum dose of 12.2 % (v:v, %), industrial wastewater concentration of 4%, initial pH values of 6.5, loading liquid of 60 mL/250 mL, and culture time of 24 h. Culturing with the optimal fermentation conditions resulted in the biomass of B. cereus of 1.35 ± 0.02 × 109 Obj/mL (N = 3), which was consistent with the predicted values (1.32 × 109 Obj/mL) predicted by the corresponding regression models (p < 0.05), and more, was also far higher than that of the standard of agricultural bacterial fertilizers in People’s Republic of China. Further, the results of field trial indicated that the of B. cereus liquid fertilizer can remarkably enhance the yield of Brassica chinensis L. It is practicable to make use of the industrial wastewater of A. bisporus to prepare the microbial fertilizer.

Optimization of fermentation conditions for the production of acidophilic β-glucosidase by Trichoderma reesei S12 from mangrove soil

Vegetative biomass contains a large number of macromolecular substances such as cellulose and hemicellulose, which can be used by microorganisms to produce biofuels and other chemical byproducts. In this study, a filamentous fungus with high β-glucosidase activity was isolated from mangrove soil in Hainan Province, China. Through morphological identification and internal transcribed spacer (ITS) sequence analysis, the strain was identified as Trichoderma reesei. Fermentation conditions were optimized with the response surface method to improve β-glucosidase activity. Inoculum, pH and liquid volume in flask were found to be the key factors. We further examined the optimal range of the three factors using steepest ascent path, and optimum conditions were further investigated according to a Box-Behnken design. We calculated the optimized fermentation conditions to be: carbon source (microcrystalline cellulose (MCC)) 1%, nitrogen source (yeast extract) 0.5%, pH 3.68, inoculum of 3.22 × 105 cfu/mL, temperature 28 °C, shaking speed of 160 rpm, and liquid volume in flask of 84.74 mL/250 mL. These conditions increased the β-glucosidase activity 6-fold to 1.13 U/mL compared to that before optimization. The resulting β-glucosidase had an optimum pH of 5.0 and an optimum temperature of 45 °C, and showed high thermal stability at 30-60 °C.

Medium Optimization for Spore Production of a Straw-Cellulose Degrading Actinomyces Strain under Solid-State Fermentation Using Response Surface Method

The strains capable of degrading cellulose have attracted much interest because of their applications in straw resource utilization in solid-state fermentation (SSF). However, achieving high spore production in SSF is rarely reported. The production of spores from Streptomyces griseorubens JSD-1 was investigated in shaker-flask cultivation in this study. The optimal carbon, organic nitrogen and inorganic nitrogen sources were sucrose, yeast extract and urea, respectively. Plackett–Burman design (PBD) was adopted to determine the key medium components, and the concentration levels of three components (urea, NaCl, MgSO4·7H2O) were optimized with the steepest ascent path and central composite design (CCD), achieving 1.72 × 109 CFU/g of spore production. Under the optimal conditions (urea 2.718% w/v, NaCl 0.0697% w/v, MgSO4·7H2O 0.06956% w/v), the practical value of spore production was 1.69 × 109 CFU/g. The determination coefficient (R2) was 0.9498, which ensures an adequate credibility of the model.

Optimization of three-phase fluidized bed cell disruptor for the release of alcohol dehydrogenase from baker’s yeast

A three-phase fluidized bed cell disruptor equipped with a multi-disk impeller was applied in the disruption of baker’s yeast cells for the release of alcohol dehydrogenase (ADH). The performance of cell disruption was assessed by the kinetics of disruption contributed by different operation parameters. The operating conditions of cell disruption, including rotational and linear speed of impeller, cell mass concentration, percentage volume of glass bead, duration of operation, and rate of gas bubbling, were optimized by design of experiment method. Based on the first-order model derived using path of steepest ascent, it was found that the rotational and linear speed of impeller, cell mass concentration, and percentage volume of glass bead were the significant process parameters. The optimal values of these parameters were then predicted using central composite design of experiments. As predicted with a second-order polynomial model, the maximum release of ADH was achieved under the operating conditions: agitator speed of 5000 rpm, 25% (ww/v) of cell mass concentration, 1500 mL of glass bead, 10 L/min of gas bubbling and operating duration of 5 min. The maximum release of ADH obtained from the experiment under the optimal conditions was 329.8 U/min/dw-cell, which was close to the value of 331.2 U/min/dw-cell predicted by the response surface model.

High-fold improvement of assorted post-consumer poly(ethylene terephthalate) (PET) packages hydrolysis using Humicola insolens cutinase as a single biocatalyst

Abstract The dissemination of technologies for poly(ethylene terephthalate) (PET) recycling is of paramount importance in the context of the plastics circular economy. One of the most promising alternatives is to use enzymes as catalysts for PET depolymerization to its monomers, but this route still needs improvement, especially regarding titer and productivity. In the present work, a sequential approach comprised of fractional factorial and central composite rotatable designs, the path of steepest ascent and one-way evaluation of variable effect, was performed to address these limitations, during assorted post-consumer PET (PC-PET) hydrolysis catalyzed by Humicola insolens cutinase. The highest terephthalic acid concentration and productivity during PC-PET hydrolysis were 100.9 mM (16.8 g/L) and 14.4 mM/day, corresponding to overall improvements of 10-fold and 20-fold, respectively. These data are among the best results described so far for enzyme-catalyzed hydrolysis of used PET packages. Also, the use of a single enzyme system, instead of multiple biocatalysts to achieve final conversion of PET to its monomers, lowers the process complexity and costs.

Medium composition optimization, structural characterization, and antioxidant activity of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi

To contribute towards effective exploitation and utilization of natural antioxidants, response surface methodology (RSM) was employed to optimize the medium composition for the production of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi (GLEPS). An optimal medium for GLEPS production was gave through Plackett-Burman design, path of steepest ascent, and Box-Behnken design as follows: glucose (59.62 g/L), yeast extract (10.03 g/L), CaCO3 (0.2 g/L), thiamine (45.13 mg/L), KH2PO4 (1.0 g/L), peptone (1.5 g/L), Tween 80 (10.26 mL/L), ZnSO4 (0.3 g/L), mannitol (1.5 g/L), MgSO4 (0.5 g/L), and aspartate (8.86 g/L). The GLEPS yield obtained was 3.57 ± 0.21 g/L-3.16-fold higher than that produced in basal medium alone. The resulting GLEPS rich in uronic acid, d-mannose, l-rhamnose, and d-glucose, was a heteropolysaccharide with high-molecular weights (475,000 kDa and 21.6 kDa, 87.97%). It was demonstrated that the GLEPS with higher carbohydrate and uronic acid contents exhibited strong in vitro antioxidant activities via radical scavenging, reductive capacity, and chelation of transition metal catalysis. These findings indicated that RSM is an efficient tool to predict the composition of culture medium required for maximizing GLEPS yield, and GLEPS had potent antioxidant activities and could be explored as a novel natural antioxidant in functional food or medicine.

Facile development of medium optimization for antibody production: implementation in spinner flask and hollow fiber reactor.

Most bio-industrial mammalian cells are cultured in serum-free media to achieve advantages, such as batch consistency, suspended growth, and simplified purification. The successful development of a serum-free medium could contribute to a reduction in the experimental variation, enhance cell productivity, and facilitate biopharmaceuticals production using the cell culture process. Commercial serum-free media are also becoming more and more popular. However, the cell line secrets its own recombinant product and has special nutritional requirements. How can the composition of the proprietary medium be adjusted to support the specific cell's metabolism and recombinant protein? This article uses statistical strategies to modify the commercial medium. A design of experiments is adopted to optimize the medium composition for the hybridoma cell in a serum-free condition. The supplements of peptone, ferric citrate, and trace elements were chosen to study their impact on hybridoma growth and antibody production using the response surface methodology. The stimulatory effect of the developed formulation on hybridoma growth was confirmed by the steepest ascent path. The optimal medium stimulated the hybridoma growth and antibody production in three diverse systems: a static plate, an agitated spinner flask, and a hollow fiber reactor. The cells in the developed serum-free medium had a better antibody production as compared to that in the commercial medium in the hollow fiber reactor. Our results demonstrated that the facile optimization for medium and antibody production was successfully accomplished in the hybridoma cells.

Optimization of Xylanase Production by Trichoderma orientalis Using Corn Cobs and Wheat Bran via Statistical Strategy

In order to obtain the best conditions for xylanase production, statistical experimental designs were applied for improvement of xylanase yield by Trichoderma orientalis EU7-22 using corn cobs and wheat bran as raw materials. Plackett–Burman design was applied to evaluate the effects of eight variables (concentration of peptone, tween-80, CaCl2, MgSO4, FeSO4, as well as initial pH, fermentation temperature, fermentation time). The key factors influencing on xylanase production were identified as the fermentation time, concentration of MgSO4, and fermentation temperature. And then the path of steepest ascent was carried out to approach the optimal region of the three significant factors. These variables were subsequently further investigated by Box–Behnken design of response surface methodology. The optimum conditions for xylanase production were obtained as fermentation time 72 h, concentration of 0.08% for MgSO4, fermentation temperature 37.3 °C, and the xylanase activity increased from 107.6 to 269.4 IU/mL, which was a 150% increase. It was found that the higher temperature (37.3 °C) was more suitable for xylanase production than low temperature (30.0 °C) in T. orientalis EU7-22. The statistical experimental design was proven as an effective method to obtain optimum parameters for xylanase production. The mixture of corn cobs and wheat bran as substrates could greatly improve the xylanase yield, in comparison with corn cobs alone, wheat bran alone, and Avicel supplement with wheat bran as inducer substrates, respectively.

Optimization of key factors affecting bio-hydrogen production from sweet potato starch

Key factors affecting the bio-hydrogen production from sweet potato starch were optimized by response surface methodology (RSM) with Box-Behnken design. Sweet potato concentration, FeSO4 concentration, and initial pH were identified by Plackett-Burman design as the significant factors. The path of steepest ascent and Box-Behnken design were subsequently applied to optimize the levels of the significant variables. The results indicated that the concentration of sweet potato starch, and the interaction between pH and FeSO4 concentration significantly affected the cumulative hydrogen production. The maximum cumulative hydrogen production of 3501 mL/L was achieved under the optimum conditions of the initial pH of 6.05, sweet potato starch concentration of 27.63 g/L, and FeSO4 concentration of 63.17 mg/L.

The augmentation of existing data for improving the path of steepest ascent

ABSTRACTResponse surface methodology is a collection of mathematical and statistical techniques that are useful for the modeling and analysis of problems in which a response of interest is influenced by several independent variables and the objective is to optimize this response. When we are at a point on the response surface that is remote from the optimum, such as the current operating conditions, there is little curvature in the system and the first-order model will be appropriate. In these circumstances, a preliminary procedure as the steepest ascent usually is employed to move sequentially in the direction of maximum increase in the response. To improve the estimation of parameters of the steepest ascent path, we present, in an efficient way, the augmentation of existing data such that the independent variables are made more orthogonal to each other. Additionally, when we estimate the true path using this method, the bias and magnitude of the covariance matrix of the estimated path is decreased, significantly.

Optimization of an alcoholic-alkaline freeze-drying treatment for granular cold-water swelling starches

Using native maize starches as raw materials, this paper studied the process optimization of alcoholic-alkaline freeze-drying treatment to prepare granular cold-water swelling (GCWS) starches. In this work, three statistical approaches, specifically, Plackett-Burman, steepest ascent path analysis and Box-Behnken design, were combined to investigate the effects of major treatment process variables, including the ethanol concentration, sodium hydroxide dosage, alcoholic-alkaline treatment reaction time, and drying operation, that is, the vacuum degree, drying time and material thickness, on cold-water solubility. The results revealed that the ethanol volume fraction, sodium hydroxide dosage and vacuum degree were significant factors. Maximum cold-water solubility was obtained when the optimum volume fraction of ethanol and sodium hydroxide dosage were 43.32% and 58.43 mL, respectively, and when dried at 56.42 Pa of vacuum degree. The theoretical values (89.6%) and observed values (85.3%) were in reasonable agreement, and the deviation was less than 1%. The verification and repeated trial results indicated that the alcoholic-alkaline freeze-drying treatment could be successfully used for preparation of GCWS starches at room temperature and greatly improved cold-water solubility.

Optimization of Cultural Conditions for Antioxidant Exopolysaccharides from Xerocomus badius Grown in Shrimp Byproduct.

To optimize the production conditions for exopolysaccharides with higher antioxidant activities from Xerocomus badius cultured in shrimp byproduct medium, Plackett-Burman design, path of steepest ascent, and response surface methodology were explored. Based on the results of Plackett-Burman design and path of steepest ascent, a Box-Behnken design was applied to optimization and the regression models. The optimal cultural condition for high yield and antioxidant activity of the exopolysaccharides was determined to be 10.347% of solid-to-liquid ratio, a 4.322% content of bran powder, and a 1.217% concentration of glacial acetic acid. Culturing with the optimal cultural conditions resulted in an exopolysaccharides yield of 4.588 ± 0.346 g/L and a total antioxidant activity of 2.956 ± 0.105 U/mg. These values are consistent with the values predicted by the corresponding regression models (RSD < 5%).

Optimization of Biosorption of Reactive Blue 222 by Dead Biomass of Rhizopus arrhizus NCIM997 Using Response Surface Methodology

The present investigation deals with utilization of dead fungal biomass of Rhizopus arrhizus NCIM 997 as a low-cost biosorbent and optimization of conditions for the removal of Reactive Blue 222 dye from aqueous solution using sequential statistically designed experiments. Plackett - Burman design with six independent variables (pH, concentration of dye, concentration of biosorbent, temperature, speed of agitation and contact time), was used initially to identify the most significant factors influencing biosorption. Path of Steepest Ascent was then used to move towards the vicinity of optimum operating conditions. Central Composite Design at the specified combinations of four significant factors identified by Plackett–Burman Design (pH, concentration of dye, concentration of biosorbent, contact time) and response surface analysis were then adopted to investigate mutual interactions between these variables and to identify their optimal values. The maximum sorption (72.89 mg g-1) was obtained under following conditions: pH 1.5, initial concentration of dye 88 mgL-1, concentration of biosorbent 1.2 gL-1 and contact time 111 min. Validation experiments showed excellent correlation between predicted and experimental values. The fitted quadratic model was used to arrive at the best operating conditions to achieve a maximum response. The sequential optimization was successfully used to increase biosorption by 12.82%.